Zylinder

Hello

I install a new cam in my 1989 Iroc-Z with 305 TPI engine.
What are the parameters of the cam where you cannot use the stock timing chain ? I ask this question because the change is expensive (Timing set 100$, Timing Cover 80$, problems with water pump clearance, ...)

Thanks

c4mo

iTrader: (3)

It is important to change the timing chain because it will be stretched from the miles put on the engine, which affects effective cam timing. A single roller cloyes timing chain will be fine. You will be fine using your stock timing cover with new gaskets.
Also you will have no water pump issues because of the factory hydraulic roller having a block mounted retainer plate. This eliminates the need for a cam button, therefore no water pump clearance issues.
As for cam selection go small because a stock tpi 305 intake will only make power to 5300 rpm or so. A zz4 take out cam is a good choice for cheap, a small lunati voodoo cam would work well also.
https://www.lunatipower.com/Product.aspx?id=1987&gid=289
You will need the valve springs to match whatever cam you decide to choose.
Keep the lsa at 112-114
Duration at .050 no larger than 225-226
Lift will be below .550 with 1.5 rockers
Roller tip rockers will be fine 1.5 or 1.6int/1.5 exh ratio
Pcmforless for the tune.
Headers and a 3 inch mandrel exhaust need to happen before a cam is upgraded if not already done so.
When in doubt search on here for info.

tom3

Timing sets at Jegs from under $50, Edelbrock for just over $50. Money well spent. Stock chain in good shape would probably do the job though.

Fast355

iTrader: (2)

Single roller GMPP chain for engines like the ZZ4 and ZZ383 are only $50 and fit under the stock cover.

Vader

...And is far stronger than a double-row aftermarket chain. It might be a wee bit heavier, but is substantially more durable.

Zylinder

I take the CompCam 08-501-8 with 212 int./218 exh at 0,05 and 0,495lift.
I hope this cam is not to small, but i want the torque curve to be high at low to mid rpms.

ray jr

iTrader: (2)

do you have a part number on the gmpp chain ?